Packaging methods



June 22, 1965 w. F. GAUSS 3, 0, 42

PACKAGING METHODS Filed May 20, 1963 I I I 1 I I I I ixmwm A? 2mm @WWEINVENTOR. MAL/AM F. 64053 ATTOR/VE).

United States Patent 3,199,442 EACKAGHNG METHODS William F. Gauss,Pittsburgh, Pa, assignor to Mobay Chemical Company, Pittsburgh, Pa, acorporation of Delaware Filed May 20, 1963, filer. No. 231,468 8(Iiairns. (Cl. 266-463) This invention relates to packaging methods andmore particularly to an improved method for protecting packagedarticles.

Proper packaging of an article is of the utmost importance in industryin order that an article such as one that is quite delicate andfrangible can be treated and handled in such a manner that the articlewill not be damaged no matter how breakable. A manufacturer ofscientific instruments and the like cannot be plagued with the loss ordamage of his products during transit or while in storage and for thisreason great care is taken in the packaging of such frangible items andmaterials. Packaging of breakable articles is an expensive propositionand experts are continually searching for less expensive but also moreefiicient methods for accomplishing the packaging problem.

One of the heretofore known processes for packaging frangible .articlesor objects is a foam-in-place method wherein the article or object beingpackaged is Wrapped in a protective covering or wrapping, after whichthe article or object is placed in a container. Then a liquid reactionmixture is poured thereupon and this mixture reacts and forms a foamwhich surrounds the article or object. However, this heretofore knownfoam-in-place technique has some disadvantages. The foam inherently hasa tendency to stick to almost anything with which it comes in contact.It sticks not only to the Wrapping which protects the article or objectbut also to the walls of the container. As a result of the stickiness ofthe foam, difiiculties are encountered when removal of the article fromthe container and surrounding foam is attempted. The container mostlikely cannot be reused and the Wrapping surrounding the article orobject is often damaged when the package is opened. Furthermore, if thewrapping surrounding the article is bulky, the cushion formed by thefoam-in-pl-ace reaction mixture does not conform to the same shape ofthe article and void spaces occur between the article and the foamcushion. These void spaces allow the article to move and vibrate withinthe Wrapping causing damage to the article.

It is an object of this invention to provide an improved method forpackaging which is devoid of the foregoing disadvantages. It is anotherobject of this invention to provide a package that will protect anarticle from any type of shock, vibration and the like, which mightdamage the article. It is still another object of this invention toprovide a package that is efficient, easy to prepare and alsoinexpensive. It is a further object of this invention to provide apackaging method whereby the materials that are employed can be reused.

Other objects will become apparent from the following description withreference to the accompanying drawings in which:

FIGURES 1 through 4 illustrate a cross-sectional view of the steps ofpreparing a package in accordance with one embodiment of the presentinvention; and

FIGURES 5 through 7 illustrate a further embodiment of a method ofpreparing a package by a process in accordance with the presentinvention.

The foregoing objects and others are accomplished by providing acontainer, at frangible article and a foam cushion enclosed in ad-ilat-able bag wherein the dilatable bag is filled with a suitablefoam-in-place material and this bag containing the expanded foammaintains the hhihfiiz Patented June 22, 1965 frangible article orobject in cushioned and spaced rel-ation to the container. This methodof enclosing an article in a housing of foam protects the articleagainst any type of damage such as that resulting from shock-s,vibrations and the like while in transit, storage and the like.

The term dilatable as used herein identifies the bag into which thefoamed resin is inserted as one that will respond to the influence ofthe expanding foam so that it can be deformed in any direction withoutrupturing. The bag can be of a stretchable type or it can be oversizedas long as it is deformed by the force of the expanding resin and isable to substantially conform to the intricacies, crevices, cracks andthe like of the frangible article thereby assuring complete isolation ofthe article from vibrations and the like.

Referring to the particular embodiment of the present inventionillustrated in FIGURES 1 through 4 wherein a container 1 which is of anysuitable size and shape, such as, for example, square, rectangular,oblong and the like, and which can be constructed of any suitablematerial such as, for example, cardboard, wood, metal, plastic,corrugated paper and the like, has a foam cushion 2 disposed in thebottom thereof. The foam cushion 2 can be a precut slab of foam measuredto the dimensions of the base or bottom portion of the container 1 orthe foam can be prepared by pouring just enough of the fo-amablereaction mixture into the container to create the desired thickness offoam on the bottom portion of the container 1. It may be desired toenclose this foam in a dilatable bag such as one that was discussedpreviously. The article 3 which is to be protectively packaged is placedinto the container 1 and rests on the foam cushion 2 as shown in FIGURE2. It is important that the foam cushion 2 be of the proper rigidity andthickness so that it will adequately support and protect the frangiblearticle 3. After the frangible article 3 has been placed in thecontainer 1, dilatable bags 4 and 5 are also inserted into the containerbetween the frangible article and the walls of the .containcr. Asuficient amount of a foamable reaction mixture 6, so that no more isused than that required to fill the area within the container notoccupied by the article 3 when the reaction mixture has expanded, isinserted into the bags 4 and 5. The foamable reaction mixture is allowedto react and expand thus surrounding and taking the configuration of theexternal surface of the frangible article .3. The dilatable bags should:be pliable, flexible and cap-able of conforming as close as possible tothe external configurations of the frangible article as the force of theexpanding foam conforms the bags and the foam to the dimensions of thefrangible article. fhe dilatable [bags can be of any suitable size orshape and can be constructed of any type of material such as, forexample, plastic such as polyethylene, polypropylene, polyvinylchloride,paper, cotton, rubber and the like. Any suitable dila-table bag can beemployed in the practice of the present invention as long as it meetsthe requirements of being able to contain the expanding foam and conformto any particular irregularity of an article being wrapped or packaged.Preferably, the bag should not adhere in any way to the article and itshould be non-reactive with the foamin-place resin or any of thereactive components thereof.

The amount of foarnable reaction mixture being inserted into thedilatable bags 4 and 5 should preferably be calculated prior toinserting it into the dilatable bags so that preferably no more thanthat required to completeiy fill the cavity in the container notoccupied by the frangible article is used. When more than this requiredamount of foamablc mixture has been inserted into the bags, a lid canthen be placed on the container in order to limit the foaming to thearea Within the container. If just the amount of foamable mixturerequired to fill the area in the container not occupied by the frangiblearticle is inserted into the dilatable bags, a lid need not be used. Ifdesired, the container 1 may be closed by providing a lid, for example,the flap of a corrugated container immediately after the introduction ofthe foam-inplace material 6. Thus, the foam filled bags 7 and 8substantially conform to the crevices, indices and irregularitiescharacteristic of the frangible article and with the inner wall of thecontainer thereby holding the article in place in cushioned relationshipwithin the container'as in FIGURE 4. The package is now ready forstorage,

shipping and the like. The package can be easilyopened by merelyremoving the bags containing the foam cushions from the container andwhen articles of the same sizeand dimensions are being stored andshipped, the foam cush ions which are enclosed in and protected by thedilatable bags can be reused.

Referring nowrto another embodiment of the present;

into the container 9 after which a' foamable reaction rnixture 12. ispoured therein. Again, it is preferred to insertonly that amount ofthereaction'mixture into the bags 13 and 14- such as those describedhereinbefore, as thatwhich will be required to completely fill thecavity in the container not occupied by the frangible article It). Afterthe foamable reaction mixture has been inserted into the dilatable bagswhich surround the frangible article between the, Walls of the containerand the external surface of the article, the reaction mixture is allowedto react and expand within these bags. The foam cushions 15 and 16 whichare contained in the bags 13 and 14 sub: stantially surround thefrangible article 10 and protect it from substantially any damagingeffects that might be transmited to the container 9. The article is nowpackaged and can beshipped, stored, and the like. The pack age can beeasily opened by, merely removing the bags containing the foam cushionsfrom the container and when articles of the same size and dimensionsarebeing stored and shipped, the foam cushions which are enclosed in andprotected by the dilatable bags can be reused.

Foodstuffs and the like which are not capable of retaining their shapewhile-the exothermic heat of reaction is being released'by the expandingfoam can be prepared in a slightly diflierent manner. A molding typeprocedure can be followedwherein a mold made of wood or the like ispositioned in a container substantially in the same likeness as if theactual article were present. After the foam cushions are prepared inplastic bags around'the. mold, the mold can be removed and thefoodstuffs or other to act as a liquid and vapor barrier for the articleenclosed therein.

The polyurethane foams preferred in accordance with the presentinvention can be prepared by reacting an organic polyisocyanate with anorganic compound containing at least two active hydrogen/containinggroups as determined by the Zerewitinoff method and a blowing agent. Anysuitable organic polyisocyanate can be used for the preparation of thepolyurethane foam'of this invention, such as, for example, thosedisclosed in .United States Reissue Patent 24,5l4 to Hoppe et-al.,issued August 12, 195 8. Arylene diisocyanates. are preferred, vsuch as,for example, 2,4-toluylene diisocyana te, 2,6-toluylene diisO- cyanate,isomeric mixtures thereof, p,p'-diphenylmethane diisocyanate, 1,5naphthalene 'diisocyanate, triphenylmethane triisocyanate and the like.Particularly suitable arylene diisocyana'tes for this reaction is amixture of about 20 percent 2,6-toluylene diisocyanateand about 80percent 2,4-toluylene diisocyanate.

Unrefined isocyanates may alsobe used,,s uch as,'the crude-mixture ofisocyanates obtained by the phosgenation of the reaction product'ofaniline and formaldehyde which contains a mixture of diand higherpolyisocyanates or by phosgenating a mixture oftoluylene diamines whichis primarily a mixture of orthoand para-toluylene diamines. A preferredproduct is one having from about 26 to about 33; percent free -NCO andan amine-equivalent of about 120 to about 150, such as, for example, aproduct havingabout 32 percent free 'NCO and an amine equivalent ofabout 140. 7 7 Anysuitable organic compound containing at least twoactive hydrogen containing groups as determined by the Zerewitinolf testmay be used, such as, forexample, hy-

' droxyl polyesters, "polyhydric polyalkylene ethers, polythe range ofabout 1000 to 5000, a hydroxyl number of not more than about 225 andpreferably within the range of about 20 to 112 and acid numbers, whereapplicable,

"preferably below about 10 and most preferably below article to bepackaged can be substituted therefor." The foam cushioning not onlyprotects the article from vibrations, shocks and the like, it alsoinsulates the article from extreme temperatures along with providing asubstantially flameproof packaging. I

Any suitable resin capable of foaming-in-place in accordance with theforegoing description of the present invention can be used, such as, forexample, polyurethanes, polyethylenes, polyesters, epoxy resins,polypropylene, sty-i rene, polystyrene, polyvinyl alcohol and the like.In selecting a suitable foam, one having the proper rigidity orflexibility should be used since the foani-in-place resin not only holdsthe frangiblearticle in place in a container, it also tendsto absorb anyshocks, vibrations and the like that might be transmitted to thepackage. Of all the suitable foarnable'resins mentioned above, it isespecially preabout 1; V a I I 7 Any suitable hydroxyl polyester'may beused, such as,

for example, the reaction productof a polycarboxylic acid with an excessof a polyhydric alcohol. Any suitable polycarboxylic acid may be used,such as, for example, adipic acid, sebacic acid, phthalic acid,terephthalic acid, maleic acid, malonic acid, thiodipropioni-c acid andthe like. Any suitable polyhydric alcohol may be used, such as, forexample, ethylene; glycol, propylene glycol, butylene glycol, amyleneglycol, glycerine, trimethylol propane, pentaerythritol and the like.

Any suitable polyhydric polyalkylene ether may be used,'such asfforexample, the condensation'product of alkylene oxides and a polyhydricalcohol. Any suitable alkylene oxidemay be used, such as, for example,ethylene oxide, propylene oxide, butylene oxide, amylene oxide and thelike. 'It'is preferred to employ polyhydric polyalkylene ethers preparedfrom alkylene oxides having from two to five carbon atoms,'suchras, forexample, polypropylene ether glycolfpolyethylene ether glycol,polybutylenev ether glycol or mixtures thereof having a molecularweightof at least about 500. Moreover, the Icondensation products oftheaforementioned alkylene oxides and othercompounds such as polyhydricalcohols, such as, for example, ethylene glycoLpropylcne glycol,trimethylol propane, glycerol, .triethanol amine, pentaerythritol,sugars, such as glucose, fructose, sucrose and the like, ammonia,diainines and the ilikemay be used. The polyhydric polyalkyleneethersmay be prepared by anyknown process, suchas, for example, by the processdescribed by WurtZ in 18 59 and in Encyclopedia ofChernical Tech,-

' nology, Vol. 'Z, 'pages 257-262, published by lnterscienc ferred toemploy a polyurethane type resin'because of its superior sound andvibration absorbing properties. Also,

the dilatable bags which surround the foam cushions tend Publishers,Inc., 1951, or in US. Patent 1,922,459.

Any suitable polyhydric polythioethermay'be used,

C3 such as, for example, the reaction product of a polyhydric alcoholwith a thioether glycol. Any suitable polyhydric alcohol may be used,such as, for example, ethylene glycol, propylene glycol, butyleneglycol, trimethylol propane, pen-taerythritol and the like. Any suitablethioether glycol may be used, such as, for example, diethylene glycolthioether and the like.

Any suitable polyacetal may be used, such as, for example, the reactionproduct of an aldehyde, such as, for example, formaldehyde, with apolyhydric alcohol, such as, for example, ethylene glycol or one of theother polyhydric alcohols disclosed above for reaction with thepolycarboxylic acids and/ or alkylene oxides used in the preparation ofthe hydroxyl polyesters and polyethers respectively.

Any suitable polyester amide may be used, such as, for example, thereaction product of an amine, such as, ethylene diamine and an alkyleneglycol such as ethylene glycol with a polycarboxylic acid as disclosedfor the preparation of the hydroxyl polyesters.

One may also employ halo hydrocarbons either alone or with water inconjunction with the balance of the components of the cellularpolyurethane plastic. Any suitable blowing agent, which is a gas at thereaction temperature, such as, for example, dichlorodifluoromethane,trichlorofluoromethane, dichlorofluoromethane, dichlorotetrafluoroethaneand the like may be used.

It is often advantageous to carry out the reaction in the presence of acatalyst. Any suitable catalyst may be used, such as, for example,dibutyl tin di-2-cthyl hexoate, stannous octoate, triethylene diamine,N-ethyl morpholine, N-methyl morpholine, dimethyllauryl amine, ferricacetylacetonate, mixtures thereof and any other catalyst which willpromote the reaction between the isocyanate groups and active hydrogenatoms as determinable by the Zerewitinoff method such as those disclosedin Catalysis of the Isocyanate-Hydroxyl Reaction, 1. W. Britain and P.G. Gemeinhardt, Journal of Applied Polymer Science, Volume IV, Issue No.11, pages 207 to 211 (1960).

In many cases it is desirable and indeed in some cases it may benecessary to carry out the reaction in the presence of a stabilizer oremulsifier. The foam stabilizer re sults in a foam having a smaller cellsize than would be obtained with a comparable reaction mixture notcontaining the stabilizer. Any suitable alkyl silane oxyalkylene blockcopolymer such as one having the formula.

wherein R, R and R" are alkyl radicals having from one to four carbonatoms; p, q, and r each have a value of from four to eight and (C i-1 isa mixed polyoxyethylene oxypropylene block containing from to 19oxyethylene units and from 11 to 15 oxypropylene units with z equal tofrom about 26 to about 34 or similar stabilizer can be used in theprocess of the present invention. Other suitable silicone oils for thispurpose may be found in U.S. Patent 2,834,748 to Bailey et al., issuedMay 13, 1958. In the preparation of cellular polyurethane plastics fromorganic polyisocyanate modified polyhydric polyalkylene ethers havingterminal -NCO groups by reaction thereof with water, it is advantageousto employ a substantially linear dimethyl polysiloxane having aviscosity of about 50 csts. at C. The same silicone oil may be used as astabilizer in the production of a cellular polyurethane plastic based onpolyesters. Emulsifiers such as the sulfonated oils, for example,sulfonated castor oil, are also suitable.

Polystyrene foams to be used in accordance with the process of thepresent invention can be produced by introducing a foaming agent, suchas, methylene chloride under high pressure into molten polystyrene.Polystyrene foams have many tiny, noninterconnected cells, lowdensities, low thermal conductivity, good structural strength,

& form excellent water vapor barriers and can be made withself-extinguishing characteristics.

Polyvinyl alcohol foams to be used in accordance with the presentinvention can be prepared by foaming a water solution of polyvinylalcohol with air or the like in the presence of a Wetting agent, aninorganic acid and formaldehyde. Toughness, resiliency, and softness arecharacteristic of this type of foam.

Although the foregoing description tends to limit the present packagingmethods to frangible items, those items or articles which are notfrangible but require some sort of packaging can also be packagedaccording to the present invention. Any suitable container andfoam-in-place resin can be used to package an article according to thepresent invention providing the teachings of the preceding disclosureare followed.

Any suitable item can be packaged according to the present inventionsuch as, for example, sensitive electrical equipment, scientificinstruments, china, books, furniture, foodstuffs, and the like.

The invention is further illustrated by the following examples in whichthe parts and percentages are by weight unless otherwise specified.

Example 1 About parts of a mixture of about 65 parts of the propyleneoxide adduct of 1,1,3-para-hydroxyphenyl propane having an hydroxylnumber of about 223 and about 35 parts of the propylene oxide adduct ofglycerine having an hydroxyl number of about 652 mixed with about 15parts of the propylene oxide adduct of diethylene triamine having amolecular weight of about 400 and an hydroxyl number of about 700 arecombined on a machine mixer as disclosed in Reissue Patent 24,514 withabout 109 parts of the organic polyisocyanate obtained by thephosgenation of the condensation product of aniline and formaldehydewhich has an amine equivalent of about 140 and which contains about 31percent free NCO with about 40 parts of trichlorofluoromethane, about1.1 parts of 1- methyl-4-dimethyl amino ethyl piperazine and about 1part of a silicone oil having the formula:

wherein (C H O) is a mixed polyoxyethylene and oxypropylene blockcopolymer containing about 17 oxyethylene units and about 13oxypropylene units. The reaction mixture is discharged into twopolyethylene bags, one on each side of a 12" x 8" x 8" box containing amicroscope. The foam rises and sets to produce a rigid polyurethane foamhaving a density of about 1.5 lbs./ft. The foam rises in about secondsand is tack-free in about three minutes. Furthermore, the cellularpolyurethane foam produced by this process has a compression strength ofabout 20 lbs. at yield at about 8 percent deflection and this foammaintains the microscope in cushioned and spaced relationship to thebox. The microscope is now suitably packaged and protected by the foamcushion from any vibrations and shocks which might be transmitted to thebox during shipping or storing.

Example 2 About 100 parts of the reaction product ofalpha-methyl-D-glucoside with 1,2-propylene oxide having a molecularweight of about 445 and an hydroxyl number of about 525 are mixed withabout 110 parts of crude toluylene diisocyanate containing about 36.3percent free NCO, about 0.054 percent hydrolyzable chlorine, about 0.77percent total chloride, an assay of about 77 percent, an amineequivalent of about 115.6 and having a viscosity of about 220centipoises at 30 C., about 25 parts of trichlorofluoro methane, about 2parts of 1-methyl-4-dimethyl amino ethyl piperazine cone oil having theformula:

wherein (C H O) represents about 17 oxyethylene units and about 13oxypropylene units in amachine mixer such as that disclosed in ReissuePatent 24,514. After a uniform mixture is obtained, the liquid isdischarged from the mixer into a polypropylene bag which surrounds a 200watt electric light bulb suspended in a 7" x 4" x 4" paper box.Expansion of the liquid mixture occurs with the formation of a very darkin color rigid polyurethane foam having a density of about 2 lbs/ft. anda soften-. ing point of about 150 C. substantially surrounding the lightbulb yet still enclosed Within the polypropylene bag. The paper boxcontaining the foam cushion and light bulb is dropped severaltimes about6 feet onto a concrete floor. When the bulb is removed from the foampackaging it still lights.

Although the invention has been described in considerable detail in theforegoing for the purpose of illustration, it is to be understood thatsuch detail is solely for this purpose and that variations can be madetherein by those skilled in the art without departing from the spiritand scope of the invention except as set forth in the claims.

What is claimed is: a

1. A package comprising an article in a container, said container havinginner walls and outer walls, and at least one bag positioned between theinner walls of the container and the external surfaces of the saidarticle, said bag having disposed therein a cellular plastic materialwhich substantially fills the volume of the container and maintains thesaid bag in intimate contact with the exterior surfaces of the articleand the inner surfaces of the container.

2. The package of claim 1 in which the cellular plastic material is apolyurethane. foam.

3. A package comprising an article in a container, said and about 1 partof a silicontainer having inner walls and outer walls, and a pluralityof bags positioned in said container between the inner walls of thecontainer and the external surfaces of the article, said bags havingdisposed therein a cellular plastic material which substantially fillsthe container and maintains the bags inintimate'contact with and con-'formance to the surface irregularities of the said article and the innerwalls of the container.

4. The package of claim 3 in which the cellular plastic material is apolyurethane foam. 7

5. A package comprising an article, a container having inner walls andouter walls, a foam cushion, said foam cushion being situated in saidcontainer with the said article positioned thereon, and a bag locatedbetween the inner walls of the container and the external surface of thearticle and having a foam plastic material enclosed therein whichsubstantially. fills the volume of the container and maintains the bagin intimate contact with the surfaces of the article and the innerwallsof the con- References Cited by-the Examiner UNITED STATES PATENTS1,207,814 12/16 Stockton e. 53-36 2,256,939 9/41 Copeland 53-:362,472,754 6/49 Mead.

2,780,350 2/57 Simon et a1 206- 46 2,895,603 7/59 Freeman 206-46FRANKLIN T. GARRETT, Primary Examiner. EARLE J. DRUMMOND, Examiner.

Notice of Adverse Decision in Interference In Interference, No. 95,263involving Patent No. 3,190,442, V. F. Gauss, PACKAGING METHODS, finaljudgment adverse to the pzttentee was rendered June 29, 1966, as toclaims 1, 2, 3, 4, 5 and 6.

[Oficial Gazetle August .9, 1966.]

1. A PACKAGE COMPRISING AN ARTICLE IN A CONTAINER, SAID CONTAINER HAVINGINNER WALLS AND OUTER WALLS, AND AT LEAST ONE BAG POSITIONED BETWEEN THEINNER WALLS OF THE CONTAINER AND THE EXTERNAL SURFACES OF THE SAIDARTICLE, SAID BAG HAVING DISSPOSED THEREIN A CELLULAR PLASTIC MATERIALWHICH SUBSTANTIALLY FILLS THE VOLUUME OF THE CONTAINER AND MAINTAINS THESAID BAG IN INTIMATE CONTACT WITH THE EXTERIOR SURFACES OF THE ARTICLEANND THE INNER SURFACES OF THE CONTAINER.